Body Fat Calculator
Estimate your body fat percentage with just a tape measure.
How to use: Enter your height and tape measurements to estimate your body fat percentage.
How to use the Body Fat Calculator
Body fat percentage describes how much of your weight is fat rather than muscle, bone, organs and water. It is often more informative than BMI because it separates fat from lean tissue. Lab methods such as DEXA scans are the most accurate, but the U.S. Navy circumference method gives a reasonable estimate with only a tape measure.
Measure while standing relaxed. Measure the neck just below the larynx, the waist at the level of the navel (for women, at the narrowest point if you prefer), and for women the hips at the widest point. Keep the tape snug but not tight and take each measurement twice. Enter the same unit for every field and choose centimeters or inches.
The calculator applies logarithmic formulas developed for the Navy and shows your estimated percentage, a category from essential fat to above average, and, if you add your weight, the fat mass and lean mass in kilograms.
Small errors in measurement change the result noticeably, so compare readings taken the same way over weeks rather than relying on a single number. The method is less reliable for very lean or very muscular people. It is an informational estimate, not a medical assessment.
Frequently asked questions
How accurate is the Navy method?
It is typically within a few percentage points for the average person but can be less accurate for very lean, very muscular or very overweight bodies.
What is a healthy body fat percentage?
Roughly 14–24% for men and 21–31% for women is considered fitness to average, but healthy ranges vary with age.
Why do women need a hip measurement?
Women store more fat around the hips, so the formula uses waist plus hip minus neck to reflect that.